A corpora



Nov. 23, 1924 1,516,837

.C. F. VVREGHT HMJHM'LONUT TUBE ADAPTER filed April 4 1923 2 Shoals-Sheet 1 I -&r2 .1

K N TOR NOV- 25, C. F'. WRiGHT THERMIONIC TUBE Filed Anni Patented Nov. 25, 1924.

CARLETON FAY WRIGHT, OF PLYMOUTH, MASSACHUSETTS, ASSIGNOR TO WIRELESS SPECIALTY APPARATUS COI ZPANY, OE BOSTON,

TION OF NEXV YORK.

IVLESSACHUSETTS, A CORPORA- THERllliHONIC-TUBE ADA'ETER.

Appllication filed April 1 all whom it may concern:

Be it known that I, CARLs'roN FAY \Vnmn'r, a citizen of the United States of An'ierica, and a resident of Plymouth, State of Massachusetts, have invented certain new and useful 'lhcrmionic-Tube Adapters, the principles of which are set forth in the following specification and accorn anying drawings, which disclose the form oi the invention which I now consider to be the best of the various 'forms in which the principles of the invention may be embodied.

This invention relates to thermionic tube adapters.

The object of the invention is a. device which will ali'ord convenience to the radiousing ublic in permitting the employment of a tierniionic tube having a given conslruction of base and/or contact prongs, in association with a tube-socket constructed to receive a tube of different construction of base and/or contact prongs.

The invention consists of the various fea- -Lures disclosed herein and described below and in the association thereof in the adapter construction of the invention.

Of the drawings, Figs. 1-6 illustrate one form of the invention, and Figs. 7-11 illustrate another form, the form of Figs. 'i"1l being preferred.

Figure l is a side elevation of an example of a thermionic tube which is to be accommodated by the adapter herein, shown below in Fig. 2, to a tube-socket construction arranged to receive a tube of different construction of base and contactprongs from those of the tube of Fig. 1.

Fig. 2 is a side elevation, partly in section, of the adapter itself embodying in one form the .l'eatiu'es ol the invention.

Figs. 3, l and 4 show an exzunple of a tubesocket which is constructed to receive a tube base of dilferent construction from the base of the Lube of Fig. 1; Fig. 4 being a bottom plan of. such base, Fig. 3 being a veriical section (right side up) on line 3 3 of Fig. i, and Fig. t being a top plan.

5 is a top plan of the adapter of Fig.

Fig. 6 is a. side elevation, partly in section, of the construction of one of the four contact. devices {each having a prong and spring contact arrangement) of the adapter of Figs. 2 and 5.

Oi the second form of the invention shown 1923. Serial No. 629,743.

on Sheet 2, Fig. '7 is like Fig. 1 a side elevation of a thermionic tube which is to be accommodated by the adapter-construction shown below in Fig. 8.

Fig. 8 is a side elevation, partly in section (similar to Fig. 2) of the adapter.

9 is a top plan 01" Fig. 8.

Figs. it) and 11 show the construction of one of the four contact devices (each with contact prong and spring) of the adapter of Figs. 8 and 9; Fig. being a top plan of such contact device, and Fig. ll being a side elevation.

U Referring to Figs. L43, the adapter of Figs. 2, 5 and 6 is constructed to permit the mechanical and electrical coordination of the base and the contact prongs or? the tube of Fig. l. with the four circuit terminals TF, TG, Ti and TP of the socket of Fig. 4, this socket being a form designed to receive a tube having a base and contact. prongs of diil'erent constructions from those of the tube of Fig. l. The base of the tube of Fig. 1 includes four contact prongs F, G, P, F of uniform size and extension below the base. and includes also a. pin B adapted to engage a bayonet joint slot of a socket adapted to usual cm jiloyment with said tube of Fig. i, such socket not being shown. The socket of Figs. a: and t", however, is constructed to receive a tube (not shown) having four contactprongs which are generally similar to those (1 a) of Fig. 1, but one of the prongs of larger diameter and greater projection beyond the tube base than the other three contact prongs. Cf. prong 12 of the adapter of Fig. :2.) Also the prongs of the tube (not shown) to which the socket of Figs. 3, e.- and t is adapted has its prongs spaced differently with respect to one another as compared with the prongs of the tube of Fig. l, so that the latter will not enter into said socket. Also the diameter of each of the prongs oi the tube of Fig. l is dill'ereni. from that of the three prongs of the tube to which said socket oi Figs. 3, l and t" is adapted (other than the fourth prong of greater dimncter and projection from the tube) which is another reason why the tube of Fig. l. is not receivable in said socket. Also the tube normally directly rccciv'ablc in the socket of Figs. 3, -iand L is not 'lrovided with bayonet joint pin as i. of l: but the tube is held to the socket by certain springs to be described, which grip the tube-prongs. (The tube normally receivable in the socket of Fig. 4 not shown herein, being a standard commercial article. The socket, of construction suitable for the direct reception of the tube of Fig. 1, also is omitted herefrom, being likewise a standard commercial article.)

The socket of Fi s. 3 4 and 4", also a standard commercia product, consists of an 10.

insulating b se IB having a hollow lower portion (F i 4 is a bottom plan) and containing four; hook-shaped contact springs 513-46 suitably supported as shown and elecitrically connected with the four circuit tersold for use with tubes sold under the mark WD 11; but the principles of the invention may be employed in adapting other tubes to use with other sockets. Both the above tubes are constructed to have their filaments heated by current from dry cells instead of from storage batteries; and both such tubes are constructed so that users cannot destro their filaments b connecting them in soc ets adapted for otli r tubes of which the filaments are heated by current from storage batteries. In the case of the UV 199 tube, which is the form shown in Figs 1 and 7, the diameter of the base is made smaller than that of similar tubes constructed to have their filaments heated by current from storage batteries, in order to prevent users from destroying the filaments by inserting the tubes in sockets connected in receiving sets to storage batteries; also the contact-prongs separation is different, as is also the location of bayonet-joint pin B, in order to adapt the tube to a socket difl'erent from that which was adapted to storage batte tubes. An advantage of the adapter hereo in this respect is that it preserves the advantage of pieventing the user from destroying the fi ment by connecting it in a set supplied with stora e battery current, and yet ermits either 0% these two dry cell tubes 199 and WD 11) to be used with the soc et of'3, 4.and 4 adapted itself to receive di y nlg one form of dry cell tube, i. e., the one sol under the mark WD 11. This is a ve great advantage to the man thousands 0 persons using apparatus oftiskind.,.

Although the basesv and base-prongs of the gbove two types of dry-cell tubes are very and the shoul different, as indicated above, yet it happens that the clockwise succession of the four base-prongs of the UV 199 tube of Figs. 1 and 7 is the same as the clockwise succession of the contact springs of the socket of 3, 4 and 4; and on that fact the inventlon hereof premised, as will be seen.

As shown in Fig. 2,-the adapter hereof consists of a brass shell S having two difierent diameters, the internal diameter of the upper portion S being substantially smallrr than the internal diameter of the lower portion S of the shell, a shouldered portion joining shell-parts S and S. This shouldered two-diametered construction of the brass shell is obtained by the ordinary processes of cold-drawing or col pressing. The two different diameters are provided, (1) the upper one for adaptation to the tubebase of Fig. 1, and (2) the lower one to provide properly for the reception of contact devices suitable for engagement in the contact-springs of the socket of Figs. 3, 4 and 1 4". Within the lower portion S of the shell is located a base of insulating material IM which preferably extends to the shoulder portion, where it has a rounded edge, as shown, fittin the shoulder. The internal diameter of t 1e lower portion S of the shell and the diameter of insulatin base IM generally correspond with the diameter of the base of the tube to which the socket of F igs. 3, 4 and 4" is adapted for normal use. The upper or smaller internal diameter is such as to furnish a lateral support for the base of the tube of- Fig. 1. The shoulder also assists in holding base IM from vertical movement in Shell S. The internal diameter of the upper portion S of shell S is slightly greater than the outside diameter of the base of the tube of Fig. 1; and this part of the shell is left hollow 'to receive said four-pronged tube-base. 'The upper ed e of shell S is formed with a recess J apted to receive pinB of the tube base of Fig. 1 as in a bayonet joint; and pin B bears a special relation to the base-prongs of this tube which permits proper connections to be made with the contact s rin s of the socket via the adapter hereoi Iase IM is held up within shell S by means of a spinning of the 1 wer edge of the shell around .the edges 0 the.

bottom of the base as at SN, Fig. 2. Prof erably, as shown, base TM is held in place between the s un loweredges of the shell er between the shell of different diameters.

Base IM may be made, for example, from bakelite rod' or bakelite sheet, preferably canvas bakeli-te; but this base may be m0lded if desired.

'f., whmh' are locatportions S, S of v 'ormed' ,ytith f our ed four contact devir-es. the details of which are shown in Fig. U. and \\'lllt'll inelude tour prongs lli W -1:2. Fig. 2) which prejeet rigidly down heyond hase It. The knurled rhlrger-dialnet red portions K of the eontart. derives extend from top to llthtttltll of h-tse 1M. Une (ll!) of the prol'lgs PR is of l;tE; 'il diameter and gr ater downward exenetinn than th ntler three and therehy is laptli to mgage in th hi"1,;eY-dialnelel'ed of Fig. l: the howl; "it wring having; 1: largerilialneter t" an tha the Mtitt'l' t n hhol wprinn's of l. the Lllt'titl' n 'lon of .lllil IN-i111 l2 ol th L peln. its inurin h ll: 14' ol Fig. i a little ill ;ttl\';tI. tt other three fig. zt zlto the btitlict of Figs. at Ui ltl' manner than in that Willt'il 1 prearranged h the dedt ner. that til' 'tltl.

eprevented from matting wrung;

:rtiena. ot' the tith eontarl duh-es of Fig. :2 shia su in tail in Fig. t3 are idenli al with nhe all her raw for the larger Flt plunli." 1; i liileh 'ontat't derire eonlpli v- I a h:'a-.-- tlnl'tnre tullhl illfl' harrel portinl. til. thrilled at hra illl"";tl with a prong Flt (pretel'ahtr ot' inzllit-l dianletez than harl'el 13].). and a helit'zll pling llSlj' heated illtdtle hat-rel ill. and, topped i a eontaet nu-lnher h held in Pt)- sition. helow h spring llil. and ahore in; the spun upper edge S1 of the upper and open end ot' harrel Bl. In the thin lll'. tion ol the adapter, the tour ('tllltu 't d. tires are pressed into the four holes oi ltplul tlizlllletel in hzlltelite ha e l. ea th lnntaet dmier heintr formed with a htllilltti n"t".lee hi :1: the largel dianletered port stl. tn hldli it I l ght 1) in lHlbt l M. if l){t-(,. tfil ire molded. it ie molded around the tour wnita tle\'i 09; the knutlin; K thereon lJ\'-- ing their aho useful in t'ttltiiillg suelLlde- \i t'h in the haw. 'lhese four cont-art d \it'es are an positioned in their four hole; in hast I that the top eontaet Inernhem 7- 8. Fig. 2 (8 of Fig. 3) project freely it equal distances ahove the top of huSt? l.\l wfltl in the path of the proper e mtart prongs txl nding equal distanres flt idlt the tuheha-e of Fig. 1. so that when Ftlitl haw i 'ittsl in the hollow in the upper part of -.i n. and it pin B is inserted in the .i "taped noteh J and rotated anti-elo -hwne ein to hold the luhe in plaee. lhl huh wm ttPt prong (ii the tuhedlase oi Fig, .l liifd fl i and eleetrical conlael agaisl the i'tddd-LT lllt'til tl'fi H. the latter heing li -1 rezwd agalwl their helical springs (Fig. tit m that the springs act to press the tute of Fig. 1 upward and hold it in place'in the ha onel joint B. .l (Figs. 1 and Ill. Insulating haw 1M i. held from rntation within shell 5 h a part X of the shell (Fin. 2 and 7) whirh is punched into a notch e:- reee: in an adjaeenl part of the base in preparation for ueh punt-hing. This pretents Sltt'll twisting of the base as might take place olln raise when (after the tuhebase has been inserted in the shell and its eonlaet prongs have engaged with the lops of the eonlaet deriees held in haw 1) th tube is tinned to engage its pin ii in reee: J, so that said prongs are turned while hearing: on the rlpwnrdty spring-pressed t-uilta t deriets. Also a pin lN (Fig. 2 ln:\ he tX tli lktl through shell 5 and into haw Hi to preH-nt ueh relative rotation. tonlael illtlll Mt'S S h ot' the eontaet d w ri e. in the have oi the adapter are T+hapel ll 1'-l-- ---e'-tion. their upper pat-n. ron t.tut in! l wi ritl'iktl'th (lulu-h hroad-rr than th elnh' ot' the \itiltlth eontaet pron; so that although th rentewf the hool -pring ol the Ml'ht'l and th (tillers oi the adapter pron; n x-.- n t in ine with the t'tllttl' ot' the ill t'd l' htb when in th adapter. \'el there are oin hr. valid hi'oa i upper l tale id in won zl l ln -nlhew lilill will he tlltasjed hr thr l wer endil the ttlht ti -U1 1 not on! when th llt n' lil-l ntt;v th atzpter hut utt r ii iii!" h r-n turned to engage itpin ll ii. .l ht the adapter. the rolrtl'uetion and arrangelnent are h lt'l: that the luhe haw'pron r er. il tlifp the \tltlt'l\' t the top lll a 'es tit t' lll ta t lalelnitrr- The ha.--e l.\l lll:l h no lllil'v han on -half lllt'lt in thieltne (height): and the tlllwlttlltt' )\l\\'tt'll (Fig. '3) the lower end ot' harrel llli and the top snrl'are ot' t'nlltzut lneinher when depressed against *prinn llhl h the tuhe of Fig. 1. n ay he tl-rl-l--t larlel int-h; N) that nlenlher 5 l lttit 'l? nnewplartel' int-h ahove the top hwrl (i'l haw l.\l.

i le" the tuh and adapter ol Figs. 1 211.: Q ,-.pe 'ti\el are eolnhined. the. lower portion oi the adapter is ready for inner tion in the Fo-uh t of Figs. 3 and 4. so tha the iilalnent. grid and plate of the tllhe of Fig. l are pl'o| rt'l eonneeted to the tel min-ah oi the \Ht'lttl of Figs. 3 and 4: where as. in the laeh oi this adapter. the base ot the tnhe of Fig. 1 could not he used with the mt-ket of Figs. 3 and t. either lleean e none ot the corltaet prongs of Fig. 1 would engage in the eontact springs tltl of Fi 4. or, if they did, it would he po zihl and more prohahle that they would engage with the wrong springs and that ne of F tlltl eontaet prongs would not make i illilil with the hook-spring 16 of larger :halneter in Fig. at. In the tube of Fig. l. prmrj- F and F are the filament terminate, Piullg t} is the grid terminal loo and prong P is the plate terminal; in the socket of Fig. 4, springs 13 and 15 are the filament terminals, spring 14 is the grid ter minal, and spring 16 is the plate terminal; and in the adapter of Fig. 2, prongs 9 and 11 are the filament terminals, prong 10 is the grid terminal, and prong 12 is the plate terminal.

All the above is made possible by the es tablishrnent in the adapter of a proper relation between recess J and the larger con tact prong 12, thus. The larger-dianietered hookspring 16 of Figs. 3, 4 and 4 is in practice the terminal for the plate of the tube,

Ill

as stated. The joint-pin B of the base of the tube of Fig. l in practice extends from a point between plate-terminal-prong P and that one of the two filament terminals.

(F which precedes prong P in a clockwise sense. Also, as first above-stated, the clockwise succession of the contract prongs of the tube of Fig. 1 is the same as the clockw'ise succession of the springs of the socket of Figs. 3, 4 and 4". In the adapter of Fig. 2, the bayonet-joint recess J is so located at the erifery of shell S that when it is engaged y pin B of the tube of Fig. 1, the plate-prong P of Fig. 1 will make contact with contact member 8 of that contact device in base IM which comprises the larger adapter-prong 12; so that when said larger prong 12 is engaged in the larger spring 16 of the socket of Figs. 3. 4 and 4, the plate-pron P of the tube of Fig. 1 will be in electrical? connection with said spring 16 and therefore with the plate terminal TP of the socket. Thereupon the other three tube prongs of Fig. 1 will be connect-.

ed to the proper socket terminals, because of the like order of clockwise succession of the tube-prongs and the socket springs; i. e., the grid-prong G of the tube (Fig. 1) will be connected to the grid terminal TG of the socket; and the two filament terminals F, F of the tube (Fig. 1) will be connecta dFto the socket filament terminals TF and In the use of the adapter, it and the Fig. 1 tube are mechanically su ported in the socket of Figs. 3, 4 and 4, hook-springs 13-16 gripping pron s 91% of the adapter, in position in the oles in the socket, in the same manner in which said socket sn ports the tube which it is designed direct y to receive.

In the modification of Figs. 811, which generically resembles the form of Figs. 2 and 6, the shell S, having portions S and S of different inner diameters, has the lower portion of larger diameter of less vertical height that is shown in Fig. 2, and insulating base IM. therein of like vertical height. Also the spring members (58) of each of the four contact devices in base IM are the contact-members, and each is in the form of a phosphor-bronze leaf-spring bent to U-shape and having a broad top surface like the topecontact members 5-8 of Figs. 2 and 6. Eachhof the four U-shaped springs 5-8 (8 in Figs. 10 and 11) has its lower leaf-portion riveted at R (integral with K) to the rest of the contact device, and its u per end free in the hollow of shell S to e engaged directly by one of the prongs of the tube-base of Fig. 7. The hole XH (Fig. 1.0) in the lower portion of the spring through which passes rivet B (Fig. 11) offset, i. e., formed nearer one side of the spring, so that, as shown in Fig. 9, when the four broad-topped contact devices are pressed into the holes in base IM and held therein by their knurled lateral walls K, the four springs 5-8 are set close together in small compass without engagementwith one another, and yet each with ample top snare for engagement by the tube prongs which are oil-center relative to the corresponding adapter-prongs of Fig. 2 and the socket spring hooks 13-l6 Oi Fig. 4-. The con struction and arrangement are such that the tube-prongs of Fig. 1 will engage the c: ters of spring contact members eccentric rivet-hole XH (Fig. 10} is fern. ed with a lateral slot R which permitt tension into it of a part of the flare of i .vet R when the rivet is forced home; and this prevents pivotal movement of spring 8.

As in Figs. 14, the upper part of shell S of Fig. 8 is provided with a recess J so disposed in the perifery of shell S as properly to receive pin B of the tube-base of Fig. 7 as a bayonet joint, and the four prongs 912 of the adapter of Fig. 9 (prong 12 beingethe big one as before) are constructed to adapted to engage the socket of Figs. 3 and 4. Likewise, the shell S and base IM are held from relative rotation by a notch, nick or indentation N in base IM into which is unched or forced an adjacent part of Shel held between (above) the shoulder between the two parts S, S of different diameter and (below) by a lower spun edge SN or tllfi shell around the lower edge of base The form of the invention shown in Figs. 8-11 is the preferred form.

In both forms of the invention shown, the shell S has a' circular cross-section Figs. 5 and 9) and its upper interior diameter preferably is only very sli htly greater thamthe outside diameter 0 the circular base of the tube of Figs. 1 and 7, so that the innet" wall of brass shell S serves as a lateral support for the tube-base of Fig. 1,neither the broad-topped contact memher 8 of the contact devices of one of the forms disclosed (Fig. 6) nor the broadt pped fiat U spring 8 of the other form (Fig. 11) performing any function in holdl S. Base TM is ing the tube and adapter to ether. but each serving only as a means or cstablishin electrical connection between the prongs oi the tubehase'ot'Fig. l and the spring books of the socket of Figs. 23, 4 and 4".

In both forms shown. the upper portions of all four contact devi es ha re the samediameter where they lie in the four holes in base lhi (it is only the prong-part of one of the conta t devices whi h has a diti'erent diameter from the other three prongs.)

Thus the adapter hereof provides to the many users at 1nall cost the convenience of employiux: in the same socket (of Figs. 3. 4 and 4) a dry cell tube of either the UV 199 (Fig. l; or \Vl) ll type (to which the socket Fig. 4 is adapted); and that without defeating the purpose of the mtlllllfiiCiltlt of either type of tube in making it non-adapted to a storage-batery tube socket. so as to make it impossible for a careless user to destroy the filament of a. dry-cell tube by connecting it to a storage battery.

I claim:

1. A thermionic tube adapter for a tube having four contact prongs and a bayonetjoint. pin. toa socket constructed with four prong-contacts having the same clockwise arrangement as but different separation distances from such tubclprongs. said adapter comprising an insulating base in which are mounted tour contact-devices including contact-prongs projecting from one side of the base in line with the prong-contacts of the socket; a metal shell surrounding said base and extending beyond one side of the base to form a hollow receptacle for the tube. said shell being constructed with a bayonet-joint recess in its edge to receive the pin of the tube; and four U-shaped metal leaf-s )rings having their lower sides otl'sebsecnrcil to the tops of said contact. devices and their upper sides free and lying within the hollow of the shell in the path of the contact-prongs ot the entering tube.

2. thermionic tube adapter for a tube having four contact prongs, to a socket constructed with prong-contacts having the same clockwise arrangement as but ditterent scparation-di tances from said tubepronrrs. said adapter comprising an insulating base of larger dian'iete-r than the base of said tube and in which are mounted the largendiarnetercd portions of Contact devices having smaller-diametered portions constituting contact-prongs projecting from one side of said base in line with the prongcontacts of the socket: a metal shell surrounding and secured to said base and proiectin bev md the other side of the base in the form of a hollow receptacle for the tube of smaller internal diameter than the diameter of said base: and U- haped metal leaf springs having their lower sides Secured to the to s of said contact devices and their upper sid Shell in the path of the tering tube.

3. A thermionic tube adapter for a tube having four contact prongs and a bayonetjoint pin. to a socket constructed with four prong-holding contacts having! the same clockwise arrangement as but difi'erent separation distances from said tubeprongs. one of which contacts is constructed larger than the others to receive a contact prong of larger diameter than the other three. said adapter comprising an insulating base of larger diameter than the base, of said tube and in which are mounted the largerdiametered portions of contact devices having smaller-diametcrcd portions constitnh in; contact-prongs projecting from one side of said base in line with the, prong contacts of the socket. one of said prongs being of larger diameter than the other three and projectingturther than the other three to engage the larger prong-holding contact of the socket; a metal shell surrounding and secured to said base and projecting from one side of the base in the form of a hollow receptacle for the tube of smaller external diameter than the diameter of said base; and U-shapcd metal leaf springs having their lower sides secured to the top of said contact devices and the upper sides free in the. hollow of the shell in prongs of the. en-

the path of the prongs ot' the entering tube.

4. A thermionic tube adapter for a tube having four contact-prongs and a socket con structed with four prong-contacts having the same clockwise arrangement as but dill'erent separation-distances from said tube-prongs. said adapter comprising an insulating base formed with four holes having separationdistances corresponding! with those of the prongcontacts ot' the socket; four contact devices located in the holes in said base and including contaet-pron s projecting out of and beyond said base: and a metal shell embracing said insulating' base and forming a hollow space on the side of the base opposite to said projecting contact-prongs. said shell being constructed to hold the tube within said hollow space; and said contactdeviees being )rovided on their tops with Usha ed metal leaf vsprings having tree in the hollow of the hell in the path oi the contact-prongs of the entering tube,

5. A thermionic tube adapter for a tube having contact prongs and a lui vonet ioint win. to a socket having springs adapted to hold in place a second tube having contact prongs out of alinement with the prongs of said first tube. said adapter comprising a metal shell. an insulating base located in the lower part. of the shell the upper edge of the shell being constructed with a bay net joint recess to receive the pin of said first es free in the hollow of the flat ends lving tube; and contact devices located in said insulating base and comprising contact prongs extending out of the base and beyond the shell in alinement with the socket'springs; said contact devices comprising also contact members having broad surfaces extending into the hollow of the shell above the insu: lating base and in positions to be engaged by the prongs of said first tube when its base is inserted in the shell and turned to engage its pin in the recess of the shell.

6. A thermionic tube adapter for a standand four-pronged tube and a four-contact socket for a different four-pronged standard tube, which comprises a cylindrical metal sliell having an upper internal diameter slightly reater than the external diameter of the tu to be employed with it; an insulating base located within the lower portion of the shell; the upper portion of the shell being left hollow to receive within it the four: ronged base of the tube, and constructed with a bayonet-joint notch to receive the bayonet-joint pin of the base of the tube; said base and the adjacent portion of the shell having diameters generally corresponding with that otthe base of the tube to which the socket itself is adapted; and said base being constructed with four holes parallel to the axis of the shell; and four contact devices located in the holes of said base, said contact devices extending equal distances beyond the insulating base into the hollow portion of the shell in the paths of the tube-prongs, and each contact device comprisin a spring yielding to the tube-prongs and comprising also socket-contact prongs extending unyieldingly bevond the insulating base and out of the shell in positions to engage contact-devices in the socket, one of said prongs being of larger diameter and of greater extension than the other three, and said insulating base being constructed with a notch into which an adjacent part of the shell is indented, the lower edge of the shell being spun around the lower edge of the base.

7. A thermionic tube adapter for a fourpronged standard tube and a four-contact socket for a difl'crcnt four-prong standard tube, which comprises a cylindrical metal shell having an upper internal diameter slightly greater than the external diameter of the tube to be employed with it; an insulating base located within the lower portion of the shell; the upper portion of the shell being left hollow to receive within it the four-pronged base of the tube, and constructed with a bayonet-joint notch to receive the bayonet-jointpin of the base of the tube; said base and the adjacent portion of the shell having diameters generally corresponding with that of the base of the tube to which the socket itself is adapted, and said base being constructed with four holes parallel to the axis of the shell; and four contact devices located in the holes of said base, said contact devices extending equal distances beyond the insulating base into the hollow portion of the shell in the path of the tube-prongs. and each contact dcvicc comprising a spring yielding to the tubcprongs and each contact device comprising also socket-contact prongs extending unyicldingly beyond the insulating base and out of the shell in positions to engage con tact-devices in the socket, one of said prongs l'eing of larger diameter and of grcatcr ex tension than the other three; and said shell having its lower edge spun around the lower edge of said insulating base to retain the base within the shell.

8. A thermionic tube adapted for a fourpronged standard tube and a four-contact socket for a different four-pronged standard tube. which comprises a cylindrical metal shell having an upper internal diameter slightly greater than the external diameter of the tube to be employed with it; an in sulating base located within the lower por tion of the shell; the upper portion of th shell being left hollow to receive within it the four-pronged base of the tube, and constructed with a bayonet-joint notch to rc ccivc the bayonet-joint pin of the base of thc tube; said base and the adjacent portion ol the shell having diameters generally corresponding with that of the base of the tube to which the socket itselfis adapted, and said base being constructed with four holes parallel to the axis of the shell; and four contact devices located in the holes of said base. said contact devices extending equal distances beyond the insulating base into the hollow portion of the shell in the paths of the tube-prongs, and each contact device comprising a spring yielding to the tubeprongs and each contact device comprising also socket-contact prongs extending unyieldingly beyond the insulating base and out of the shell in positions to engage contact-devices in the socket, one of said prongs being of larger diameter and of greater extension than the other three; and said insulating base being constructed with a notch in which an adjacent part of said shell is indented to prevent rotation of the base within the shell by the engagement of the tube prongs with the contact devices when the tube 18 turned to engage the bayonet joint.

9. A thermionic tube adapted for a standard four-pronged tube and a four-contact socket for a different four-pronged standard tube, which comprises a cylindrical metal shell having an upper internal diameter slightly greater than the external diameter of the tube to 'be employed with it; an insulating base located within the lower portion of the shell; the upper portion of the shell being left hollow to receive within ltlf) it the four-pronged base of the tube. and constructed with a bayonet joint notch to receive the bayonet-joint pin of the base of the tube; said base and the adjacent portion of the shell havin diametels generally corresponding with that of the base of the tube to which the socket itself is adapted; and said base being constructed with four holes parallel to the axis of the shell; and our contact devices located in the holes of said base, said contact devices extendiin; t'tll lll distances beyond the insulating base into the hollow portion of the shell in the paths of the tube prongs. and each contact dcricc comprising a spring yielding to the tubeprongs and each contact device comprising also socket-contact prongs extending unyieldingly beyond the insulating base and out of the shell in positions to engage contact-devices in the socket. one of said prongs being of larger diameter and ot greater extension than the other three.

10. A thermionic tube adapter which comprises a metal shell of dillcr nt upper internal and lower; internal diameter: an insulating base located within the lower portion of the shell. the upper portion of the shell being left hollow to rec-ire within it a tour-pronged tube-base of cone sponding diameter; said insulatirg base bcing constructed with four holes parallel to the axis of the shell: and four ontact do vices in the, holes of said base. ach contact device comprising a so:ket-contact prong at one end which extends out of l shell and beyond the insulating ba c and each contact device also comprising a spring located above the prong end. and each contact device extending out above the insulating base in position to be conduclively engaged by the prongs of the upper tube-base against the yielding action bf th springs.

11. Means permitting a thaniionic tube having a given construction of ba e and contact prongs to be electrically and mechanically associated with a tubc-sockct constructed to receive a tube having dillereit construction of base and/or contact prong which comprises a metal shell: an ili lllziling base located Within the lower portion shell in the. path ot' movement of the contact prongs of the tube base inserted therein.

12. Means permitting a thermionic .tube having a given colist'tihct ion of base and contact prongs to be electrically and mechanically associated with a tube-socket constructed to receive a tubeail' ditlcrenl construction of base and/or contact prongs which coniprises a metal shell of smaller upper inter nal diameter than lower internal diameter; an insulating base located within the larger diainctcrcd portion ol the shell the upper and nialler-diimactcrcd p rt on of the she l being lcl't ll(illt)\\' 2ll1tlttillrllllt'lttl to detachably receive :i liour-pronged tube-base f con responding. dianicter; said iinulating base being constructed with tour holes parallel H the axis of the shell; and four ontact devi'cs lo'utcd in the holes of Mlltl bin-1c. each contact device comprising s ult'cl-,c!)i1t:\('[ prong at one cud ex nding out of the shell and beyond the ba e and each contact dc- \icc also coinpvi ing u pring located above the prong-end. and each iontact device ex tending abme the insulating base and int th hollow portion ol' the shell to be in position to be conductirclv engaged by the prongs ot' the upper tuhcd aec against the yielding action of the springs.

I A theriuioni tube adapter which comprist a t')lllltll'il1l nictal shell; a cylindrical insul ting ba e lo ated Within one end of the shell: the upper portion of the shell being lel'i hollow and t'oiitdltltlt'ti with a bayonet, joint recess to dctachably receive a ther iuionic tube having a lose provided with a lnrrnnctioint pin and l'our contact prongs; said base being l'ornicd with four holes parallel to the axis of said shell; and tour conta t devices carh comprising a spring and extending into the hollow interior of the shell in position to be engaged under pressuic of said springs by tlncontact prongs ol' the tube-lune wh n the latter is held by the bayonet ioil'tl ithin said hollow portion ol the shell: said contact devices each including also a conta t pron; extending out of the shell and beyond the in ulating base. one of said contact prongs being of larger diameter and ol grcatcr extension beyond the in ulating base and shell than the other otthe shell, the upper and smi lleral iametered 1 I ct; ct act. prongs.

portion of the interior of the shell bein left hollow to receive a tubebase ol' corre sponding diameter: said insulating base being constructed with tour holes parallel to the axis of the shell: and four contut devices located in the holes of said base. each contact device comprising a socket-co r tact prong at one end extending out ol the shell and beyond the insulating base and each contact device also comprising a spring: each contact device extending beyond the other end of the insnlalinj time, and into the upper hollow interior of the 14 thermi nic tube adapter which compri es a cylindrical metal shcllhaving an upper internal diameter slightl gr ater than the external diameter ol the base the tube to be employed with it: a yliudr cal insulating ll;l t located within the lower portion of the shell. the upper port on of the shell being left hollow to receive the tubc-bascz and four conta t deri es "imp rt-- ed within said insulating base and exi l e: to like distances above the insulating ose and into the hollow pi'irtion ol' the "al in positions to be engaged by the prom-s of the tube; each of said contact devices including a socket-contact prong extending out of the shell and beyond the insulating base in position to engage in a Contact device of the socket with which it is desired to use the tpbg held in the upper hollow portion of the 15. A thermionic tube adapter which comprises a cylindrical metal shell having an upper internal diameter sli htly greater than the external diameter 0 the base of the tube to be employed with it; said shell having a lower internal diameter corre- Sponding generally with the external diameter of the base of a tube to which is adapted the socket to which the adapter hereof is adapted; an insulating base located within the lower portion of said shell, the upper portion of the shell being left hollow to receive the base of the tube to be used with the adapter hereof; and four contact devices in said insulating base, extending above the base into the hollow u pper interior of the shell in positions to be engaged by the contact prongs of the tube to be employed, said contact devices also projecting down beyond the insulating base and out of the shell in positions to engage in the contact devices of the socket.

16. A thermionic tube adapter which com prises a cylindrical metal shell; an insulating base located within the lower portion of the shell; the upper portion of the shell being left hollow for the reception oi the base of the tube to be employed; and contact devices located within the insulating base and extending above and below it; the lower edge of the shell being spun around the lower edge of the insulating base to hold the shell and base together; and additional means for holding the shell and base together.

17. A contact device for a thermionic tube adapter which comprises a rod having an upper knurled surface and a lower contact prong of smaller diameter, and an integral rivet projecting from the upper end of the rod; in combination with a U-shaped leafspring formed with an ofl'set hole for the rivet in one side of the U and an adjacent recess to receive the flare of the rivet.

CARLETON FAY WRIGHT. 

